1. Field of the Invention
The invention relates to electric submersible progressing cavity pump (PCP), and more particularly, to a fluid-guiding and electric conducting system for a suspended electric submersible progressing cavity pump (PCP).
2. Description of the Related Art
Currently, ground driven PCP are widely used for extracting thick well fluid. However, ground driven PCP have many drawbacks. First, when a thin drive shaft of a ground driven PCP rotates inside of the well fluid pipe, large friction is generated between the drive shaft and the inner wall of the well fluid pipe. Large friction means that the PCP can only be operated at low rotational speeds, and thus their function cannot be utilized effectively. Secondly, even higher friction losses between the drive shaft and the inner wall of the well fluid pipe occur when the pumped well fluid has a high sand content, when the pipe slope is steep, when the suspended position of the pump is low, or when the pipe has many inflexion points. Under these circumstances, the drive shaft may be deformed or broken, the well fluid pipe may be worn out, and the PCP may fail to operate.
In order to solve the above problems, a suspended type electric submersible PCP has been developed. The driving mechanism of the suspended electric submersible PCP has an elongated structure, can be submerged into a well along the pipe, and the long drive shaft is replaced with a short flexible shaft, so that the drawbacks of above mentioned ground driven PCP are overcome. However, since the driving mechanism of a conventional suspended type electric submersible PCP is located between the well fluid pipe and the PCP, and the space inside the pipe is limited, passing the pumped well fluid through the driving mechanism into the well fluid pipe and connecting reliably the lead wire of the motor to the power supply presents a problem.